BENIGN PLEURAL SCHWANNOMA WITH PLEURAL EFFUSIONS AND NECROTIZING PNEUMONIA

SESSION TITLE: Invasion of the Pleura SESSION TYPE: Case Reports PRESENTED ON: 10/18/2022 11:15 am - 12:15 pm INTRODUCTION: Schwannoma is a well circumscribed encapsulated solitary neoplasm arising from myelin producing cells of peripheral nerve sheaths. Pleural schwannomas represent only 1-2% of thoracic tumors and rarely present with pleural effusion. To our knowledge only six cases of benign pleural schwannoma have presented with a pleural effusion to date. We present a rare case of a pleural schwannoma with bilateral serosanguinous pleural effusions complicated by necrotizing pneumonia. CASE PRESENTATION: 54 year old smoking male with no past medical history was transferred from an outside hospital after two weeks of worsening acute hypoxemic respiratory failure while being treated for necrotizing pneumonia, right sided loculated pleural effusion, and a right paramediastinal mass. His only presenting symptom was worsening dyspnea for three days. Upon arrival to our hospital, the patient was on maximal ventilator settings with two right sided chest tubes draining blood tinged pleural fluid. CTA of the chest showed a large cavitary consolidation in the right upper lobe with destruction of the lung parenchyma. Additionally, there was an intrapleural heterogenous mass in the posterior aspect of the right lung apex which abut the mediastinum measuring 9.7 x 7.5 x 10.3 cm. He was treated with zosyn for positive sputum cultures growing beta hemolytic strep group F. Patient underwent a flexible bronchoscopy with EBUS-TBNA of mediastinal lymphnodes and lung mass which was non-diagnostic. A CT guided biopsy revealed a spindle cell neoplasm with a Ki-67 of 10-20%. Immunohistochemical analysis demonstrated positive staining of the tumor cells for S-100 protein. The final pathological diagnosis was benign schwannoma. He underwent a tracheostomy and PEG and was sent to a rehab center with outpatient follow-up with cardiothoracic surgery for tumor removal. DISCUSSION: Pleural schwannomas are slow growing, rarely progress to malignancy, and are often located in the posterior mediastinum. Patients are usually asymptomatic but can present with symptoms associated with obstructive pneumonia. It is very rare for a benign pleural schwannoma to present with a pleural effusion. Literature review has revealed only six cases of benign schwannoma presenting with a pleural effusion, all of which were blood stained. Spontaneous tumor hemorrhage or cyst rupture has been a theory of etiology for the effusions. Prognostically, once the pleural schwannomas are surgically resected there is minimal chance of recurrence. CONCLUSIONS: Our case represents a benign pleural schwannoma that caused extrinsic compression on the right upper lobe bronchus leading to a necrotizing pneumonia along with bilateral serosanguinous pleural effusions. A pleural schwannoma should be considered in the differential diagnosis of intrathoracic tumors even when presenting with pleural effusions. Reference #1: Shoaib D, Zahir M, Khan S, et al. Difficulty Breathing or Just a Case of the Nerves? Incidental Finding of Primary Pleural Schwannoma in a Covid-19 Survivor. Cureus. 2021. 13(8): e17511. Reference #2: Bibby A, Daly R, Internullo E, et al. Benign Pleural Schwannoma Presenting with a Large, Blood Stained Pleural Effusion. Thorax. 2018. 73:497-498. Reference #3: Nosrati R, Annissian D, Ramezani F, et al. Benign schwannoma of posterior mediastinum accompanied by blood pleural effusion misdiagnosed as solitary fibrous tumor: A Case report. Casplan J Intern Med. 2019. 10:468-471. DISCLOSURES: No relevant relationships by Brittany Bass No relevant relationships by Oleg Epelbaum No relevant relationships by Theresa Henson No relevant relationships by Yasmin Leigh No relevant relationships by Ester Sherman No relevant relationships by Sally Ziatabar

Rare case of cystic schwannoma presenting as right upper lobe lung cyst

Background: Schwannomaare benign tumors arising from Schwann cells of nerve root sheaths. Schwannomasare mostly solid / heterogeneous solid tumours, rarely cystic. Presentation of cystic schwannomainthorax is extremely rare. Case Study: A 62-year-old female came to our hospital withthe complaint of right sided chest pain for 2 months, which is dull, non-radiating. She had history of fever 4 months back, diagnosed to have covid and took treatment at home. Chest x-ray showed a homogenous opacity in the right upper lobe extending up to 1stintercostal space. Ct reported well-defined thick-walled cyst, hypodensewith central low attenuation, forming acute angles with lung parenchyma in apical segments of right upper lobe towards mediastinum. Mild perilesional atelectasis is seen.On contrast, cyst is non enhancing. Patient is evaluated for the possibilities of Foregut duplication cyst, Hydatidcyst, Neoplasm. Endoscopic ultrasonography revealed a 5cms×5cms cyst, which is not communicating, infiltrating to esophagus. Patient was referred to ctvswhere excision of cyst is done by right thoracotomy .A 6cms×6cms×2cms unilocularcyst with wall thickness ranging from 0.1- 0.4cms. Its outer surface is congested, inner surface showed dark-brown hemorrhagic contents. Histopathological examination revealed cystic schwannoma. Discussion: Schwannomasare mostly benign in nature .Treatment includes excision of Bronchogenic cyst, Brachial cyst, neurogenic tumours, apical lung tumour, hydatid cyst, foregut duplication cyst are to be considered as differential diagnosis. It is important to consider cystic schwannomasin the differential diagnosis of thoracic cystsince the best surgical outcome is strongly related to earlier diagnosis and total resection of the lesion.